1. Technical Field
The disclosure relates to a composite material, and particularly to a carbon nanotube composite material.
2. Description of Related Art
Many novel properties are beyond traditional theories when the materials are nano-sized, which may reasonably make nano-materials the representative of modern science and technology. The potential research is highly sought because of their distinct catalytic, electronic, magnetic, and luminescent properties. A composite material having carbon nanotubes as reinforcement and as an electrical conductor as well as nano-particles have broad applications in the field of microelectronics, material science, biology, and chemistry because of good anti-static performance, microwave absorbing capability, electromagnetic shielding ability, and so on. However, the nano-particles are prone to agglomerate together. Methods have been developed to manufacture a composite which includes a plurality of carbon nanotubes with nano-particles uniformly distributed on the surface of the carbon nanotubes.
A carbon nanotube composite material includes a plurality of carbon nanotube powders and tricobalt tetraoxide (Co3O4) particles coated on the surface of the carbon nanotube powders. The carbon nanotubes and Co3O4 particles form a composite nano-powder. A typical method for making the composite nano-powder includes:                (a1) putting the carbon nanotube powders into a strong nitric acid for about 6 to about 8 hours;        (a2) introducing active functional group, for example, hydroxyl group or carboxyl group on the surface of the carbon nanotube powder;        (a3) using deionized water to clean the carbon nanotube powders which is activated by active functional group;        (a4) providing a mixture which is made by dissolving a cobalt (II) nitrate hexahydrate into an ethanol solution;        (a5) immersing the carbon nanotube powders into the mixture and vibrating by ultrasound for about 15 to about 60 minutes, so that the cobalt(II) nitrate hexahydrate are adsorbed on the surface of the carbon nanotube powders;        (a6) pouring the mixture into a silicone oil for about 5 to 10 hours to decompose the cobalt(II) nitrate hexahydrate into Co3O4 particles to obtain the carbon nanotube composite material coated by Co3O4 particles; and        (a7) cleaning the carbon nanotube composite material by ethane and ethanol.        
However, the above mentioned method is complicated, costly, and not suitable for mass production. Furthermore, strong nitric acid can be prone to pollute the environment.
A composite film material includes a carbon nanotube film on a metal substrate and nickel (Ni) nano-particles. The nickel (Ni) nano-particles are deposited on the carbon nanotube film. A method for making the carbon nanotube composite film material includes:
(b1) providing a metal substrate and a plurality of carbon nanotubes;
(b2) polishing and degreasing the metal substrate;
(b3) putting the carbon nanotubes into an acetylacetone solution and ultrasonically vibrating the solution to obtain a carbon nanotube suspension;
(b4) using the metal substrate as a cathode and supplying a direct current into the suspension to deposit the carbon nanotubes on the surface of the metal substrate and forming a carbon nanotube film on the metal substrate; and
(b5) placing the metal substrate on a carbon nanotube film deposited into a plating solution with Ni, and coating Ni nano-particles on the surface of the carbon nanotube film by electroplating to obtain the composite film material.
However, in this method, the Ni particles are prone to agglomerate together. Furthermore, the method is complicated, costly, and not suitable for mass production.
Therefore, there is room for improvement within the art.